The three major techniques used in STRUTS2:
1. Data echo
2. Model-driven
3. Prevent duplicate submission of forms
First, data echo:
1, data echo, you must use the struts tag.
2. Code Explanation:
1) Action:
Go to modify page public
String viewupdate () {
///Impersonate an object (get an ID first, and then call the service query based on the ID to save the found result to the domain)
User userInfo = new User ();
Userinfo.setusername ("Endeavor");
Userinfo.setemail ("Endeavor@163.com");
Actioncontext AC = Actioncontext.getcontext (); map<string,object> request = (map<string, object>) ac.get ("request"); request.put ("UserInfo", userInfo);
/************* data echo ***************/
//Get value stack
valuestack vs = Ac.getvaluestack ();
Vs.pop ();//Remove stack top element
Vs.push (userInfo); into
the stack//Enter
the change page return "Viewupdate";
}2) JSP page:
<body>
<% @taglib uri= "/struts-tags" prefix= "s"%>
<br/>
<!--in the page text box, display the data to modify the record-- >
<!--manually set the value displayed by value
<s:form action= "#" >
user name: <s:textfield name= "User.username" value= "%{#request. Userinfo.username}" ></s:textfield> <br/>
Email: <s:textfield name= "User.email "Value="%{#request. Userinfo.email} "></s:textfield> <br/>
</s:form>
-
<!--data echo technology: S:textfield automatically finds root element data (OGNL expression language value)--
<s:form action= "#" >
Username: < S:textfield name= "UserName" ></s:textfield> <br/>
Email: <s:textfield name= "Email" > </s:textfield> <br/>
</s:form>
<s:debug></s:debug>
</body >Ii. prevent duplicate submissions of forms
Core: Struts provides protection against form repeat-commit interceptors:
<interceptor name= "token" class= "Org.apache.struts2.interceptor.TokenInterceptor"/>
Explain it through the case:
1, update.jsp
<%@ page language= "java" import= "java.util.*" pageencoding= "UTF-8"%> <% @taglib uri= "/struts-tags" prefix= "s" %> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >2, list.jsp
<%@ page language= "java" import= "java.util.*" pageencoding= "UTF-8"%> <% @taglib uri= "/struts-tags" prefix= "s" %> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >3, add.jsp
<%@ page language= "java" import= "java.util.*" pageencoding= "UTF-8"%> <% @taglib uri= "/struts-tags" prefix= "s" %> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >4, Employeeaction.java
public class Employeeaction extends Actionsupport implements modeldriven<employee>{/**** package data ****/Private Employee Employee = new Employee (); Public employee GetEmployee () {return employee; } public void Setemployee (employee employee) {This.employee = employee; }//Overriding the model-driven method @Override public employee Getmodel () {return employee; }/**** called service****/private iemployeeservice EmployeeService = new EmployeeService (); /** * 1. Add Employee */public String Save () {try {//Call service Save Employeeservice.save (employee ); Add the success, go to the list page return lists (); return "Addsuccess"; } catch (Exception e) {e.printstacktrace (); return ERROR; }}/** * 2. List Display */public String list () {try {//query all list<employee> listemp = Emplo Yeeservice.getall (); Save to request Domain Actioncontext.getcontext (). Getcontextmap (). Put ("Listemp", listemp); return "List"; } catch (Exception e) {e.printstacktrace (); return ERROR; }}/** * 3. Go to modify page */public String viewupdate () {try {//3.1 Gets the primary key value of the currently modified record int id = employ Ee.getid (); 3.2 Service Query Employee EMP = Employeeservice.findbyid (ID); 3.3 Data echo//A. First get the value stack valuestack vs = Actioncontext.getcontext (). Getvaluestack (); Vs.pop (); Remove stack top element Vs.push (EMP); The EMP object is placed on top of the stack return "update"; } catch (Exception e) {e.printstacktrace (); return ERROR; }}/** * 4. Modify Employee */Public String update () {try {//Invoke service modification Employeeservice.update (Empl Oyee); return list ();} catch (Exception e) {e.printstacktrace (); return ERROR; } } }5, Struts.xml
<?xml version= "1.0" encoding= "UTF-8"?> <! DOCTYPE struts Public "-//apache software foundation//dtd struts Configuration 2.3//en" "http://struts.apache.org/ Dtds/struts-2.3.dtd > <struts> <!--change Theme--<constant name= "Struts.ui.theme" value= "simple" ;</constant> <package name= "emp" extends= "Struts-default" > <!--Global View--<globa l-results> <result name= "error" >/error/error.jsp</result> </global-results> <action name= "emp_*" class= "cn.itcast.action.EmployeeAction" method= "{1}" > <!--Prevent forms from repeating commits, step two: Configure "Prevent forms from repeating the interceptor"--<interceptor-ref name= "Defaultstack" ></interceptor-ref> <inte Rceptor-ref name= "token" > <!--Specifies which methods need to be blocked from repeating the form (save)--<param name= "inclu Demethods ">save</param> </interceptor-ref> <!--prevent formsRepeat commit, step three: If the user repeatedly commits a jump to the specified error page--<result name= "Invalid.token" type= "Redirectaction" >emp_list</re Sult> <!--home Display-<result name= "list" >/WEB-INF/list.jsp</result> <!--go to the edit page-<result name= "Update" >/WEB-INF/update.jsp</result> <!-- <result name= "addsuccess" type= "redirectaction" >emp_list</result>-< ;/action> </package> </struts>
Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
